Performance is getting reduced while processing merge join in SSIS

Hi everyone,
I am trying to perform Merge Join using OLE DB source task in SSIS package. I am trying to process millions of records in the package. But I don’t know why it was taking so much time to do this simple task. Then I checked the log file and noted that it was taking so much time to sort the incoming data. But, I have already used “order by” clause in the SQL source statement for the sorting purpose. Can anyone tell how to improve the performance in this task and reduce the processing time?
Thanks!
